Means for preventing explosions in mines.



A. H. STOW. MEANS FOR PREVENTING EXPLOSIONS IN MINES.

APPLICATION FILED FEB. 28. 910.

Patented June 5, 1917.

WITNESSES i I Attorney W:

A. H STOW. MEANS FORPREVENTING EXPLOSIONS IN MINES.

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Patented June 5, 1917.

5 SHEETS-SHEET 2- INVENTOR WITNESSES Allomey A. H. STOW.

MEANS FOR PREVENTING EXPLOSIONS IN MINES.

' APPLICATLON FILED FEB. 28. I910.

Patented June 5, 1917.

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A. H. STOW.

MEA NS FOR PREVENTING EXPLOSIONS N MINES.

' APPLICATION FILED FEB. 28. 19W.

I Patented June 5,1917.

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A. H. STOW.

MEANS FOR PREVENTING EXPLOSIONS IN MINES.

Patented June 5, 1917.

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APPLICATION FILED FEB. 28, 1910.

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AUDLEY HART STOW, OF MAYBEURY, WEST VIRGINIA.

MEANS FOR PREVENTING EXPLOSIONS IN MINES.

Specification of Letters Patent.

Patented June 5, 1917.

Application filed February 28, 1910. Serial No. 546,420.

To all whom it may concern:

Be it known that I, AUDLEY H. slow, a citizen of the United States of America residing at Maybeury, in the county of Mo- Dowell, in the State of West Virginia, have invented certain new and useful Improvements in Means for Preventing Explosions in Mines, whereof the following is a specification.

This invention is more particularly applicable to mines having either the pressure system of ventilation or the obstructed exhaust system of ventilation; it relates however to means operative in connection with any system of. ventilation, for maintaining a thoroughly moist or saturated condition of the air in the mine whereby floating dust is prevented and dust explosions avoided.

Figure 1 represents a plan view of a section of a coal mine having one form of this invention installed in the intake airway thereof.

Fig. 2 represents a longitudinal vertical section on line 22 of Fig. 1. i

Fig. 3 represents a transverse section on line 33 of Fig. 1.

Fig. 4 represents a horizontal section of a part of a coal mine and a plan of one form of air saturater arranged longitudinally in the airway thereof.

Fig. 5 represents a vertical transverse section on line 55 of Fig. 4.

Fig. 6 represents a longitudinal section on line 66 of Fig. 4.

Fig. 7 represents on an enlarged scale a transverse section of the air saturater shown in Figs. 4c, 5 and 6.

Fig. 8 represents a horizontal longitudinal section of fragments of an airway provided with a connected series of the appa ratus for preventing explosions.

Fig. 9 represents a plan view of a section of the intake air-way of a coal mine showing the relation of a set of rotary sprays and a steam jet, to the travel of the ventilating current of air.

In Figs. 1, 2 and 3 the invention is illustrated as applied to an ordinary bituminous coal mine in which the pressure system of ventilation is employed. In this case the coal seam A disposed between the lower layer of slate which constitutes the floor B of the mine and the upper layer of slate which constitutes the roof C thereof has cut through it an airway D and an entry or haulage way E. The airway D serves as the ventilating intake airway in which a forced ventilating current F as indicated by the arrows is maintained by suitable mechanical means. The entry E serves, as usual in such mines, a double purpose of a haulage way and an outtake airway through which the ventilating current Gr moves outward. These ways are shown as disposed substantially parallel and separated from each other by the pillars H of unmined coal which support the roof. These pillars form intermediate passages I adapted to connect the ventilating intake airway D with the haulage and outtake E. The usual partitions J are disposed between the pillars, preferably adjacent to the airway D, and serve to cut off connection between it and the haulage way, said partitions being open or omitted at the inner end of'the mine or at any desired point, to permit the air to pass from the inlet airway D into the outlet air and haulage Way E.

The means for preventing dust explosions in coal mines, herein claimed, have for their object the artificial saturation of the intake air with moisture.

To such end a sprayer 10 adapted to discharge water in fine jets, streams, vapor or .spray is disposed near the top of the intake air-way D. This sprayer may be of any construction suitable for this purpose. As shown in Figs. 1 and 2 the sprayer comprises a D-shaped pipe having a series of jet nozzles through which spray is discharged. The supply pipe supplying the sprayer-s is however preferably provided with a readily removable strainer, the apertures in which are at least as small as those in the jet nozzles, the number being such that the resistance incident to the strainer, is not material in comparison with the pressure available.

The sprayer may also be any one of the number of well known devices for this purpose, as for instance, one or several rotary sprayers.

Means are provided for supplying the sprayer with water under pressure. Any suitable means of supply may be employed. The means shown comprise a rotary pump 20 and an electric motor 25 for driving said pump. The pump has a suction pipe 21 connected with a suitable source of water supply and a delivery pipe 23 connected with the sprayer 10. The suction pipe 21 is provided in Fig. 3 at its inlet with a strainer 22.

A depression 30 either natural or artificial in the mine fioor may constitute a reservoir water trickling down said surfaces.

or receptacle for the water to be sprayed. This reservoir is supplied with water primarily and from time to time or continuously as required by means of a pipe 35 or otherwise connected with any water source. The reservoir is arranged to collect or receive the surplus or excess water passed through the sprayer and not absorbed by the ventilating current.

An evaporator of any suitable form may be disposed in the airway D at a proper distance from the sprayer 10 to receive water therefrom and to further expose it to the action of the air current passing through said airway. The sprayer is preferably so arranged as to discharge the water in the direction of the moving air current and the evaporator is disposed some distance behind the sprayer in position to receive water therefrom. The evaporator 40 shown in Figs. 1, 2, 3, comprises a vertical series of inclined shelves 41 having drip nozzles 42. These shelves or plates are downwardly inclined. from the rear edges thereof toward the front edges thereof and the air in passing between the plates impinges against the inclined surfaces thereof and absorbs the The surplus water, which is not absorbed or evaporated into the air, passes through the nozzles 42 into the collecting tank or reservoir 30 and is thence forced again through the sprayer.

The front edges of these plates or shelves have upturned lips 48 forming troughs for the passage of the surplus water and downturned lips 49 at their rear edges, which tend to direct or restore the air current to its horizontal course.

Sprays which are directed only in the direction of travel of the air, either with or against the air current, and as near the roof as may be practicable are the most economical in water, in that the spray will not thus be thrown on the ribs or roof, while the drops of water will have the maximum height of air to fall through before reaching the floor; if the spray is directed with the air current, and at a higher velocity, it will tend to increase the velocity of the air current, whereas if directed against same, it will have a certain tendency to retard the air current.

Circular or rotary sprays, while uneconomical in water to a certain extent, require however less piping, which only too often is of more importance than economy in water. One single line of piping in the center of the air-way, with a series or set of rotary sprays, see Fig. 9, will give the same degree of saturation, as a much greater amount of pipe, with secondary lines across the air-way, as in Figs. 3, 4 or 8 One rotary spray preferably in the center of the air-way, will serve almost the same purpose as a secondary line across the air-way. Where the velocity of the air is high, as it will usually be at the spray station, relatively little spray will be thrown against the ribs or walls of the said air-way, see Fig. 9, if the sprays are in the center of the air-way. Rotary sprays have the axis of rotation preferably vertical, as if placed near the roof as they should be, and if the plane of rotation is vertical, a large amount of water will be thrown against the roof.

Owing however to the fact that air takes up moisture more and more slowly as the saturation point is approached, and that the capacity of the air to absorb or carry moisture is increased as the temperature is raised, it is preferable, Where steam is available, to add a steam jet, on the inside of or to the rear of the water jets; that is farther along the route of the intake air from the point of intake; by this means we can reproduce summer conditions, acknowledged the least dangerous from dust explosions, during the winter, generally conceded to be the most dangerous; in the absence of artificial saturation with moisture, of the intake air. As however exhaust steam is not generally available, it being commonly necessary to generate steam for the purpose, it is under these conditions essential to economy of operation, to lncrease the saturation of the intake air by means of water sprays to a maximum, as heretofore outlined leaving as little steam required as possible; the extent to which practically the same result may be obtained by the use of sprays alone, without steam, depending largely upon the fineness of the spray; it being borne in mind that even if no steam is used, every pound of water put into the intake air, reduces the danger of explosion, by just that much, as the moisture surrounding a particle of dust serves as a bond to retain it in contact with timbers, roof or floor, and thus prevent it remaining in suspension in air, where it may assist to produce a disastrous explosion. As shown in Fig. 9, the pipe 17 0 conveys into the intake air, steam from any available source, to a point inside the rotary sprays. If sufficient steam be introduced to more than complete the saturation of the air, the excess will be deposited on roof and timbers. thus reproducing in winter the familiar sweat of the summer season.

In Figs. 4, 5, 6 and 7 the sprayer and 'iQQ-FERE axi'aneuzsszzss,

throw water in the form of jets, spray or otherwise. The evaporator comprises a series of longitudinal evaporating plates 71 disposed insaid airway between and in alternation with said spray pipes 75. These evaporating plates, pre erably vertical as shown, are preferably composed of brattice cloth stretched on frames, the frames being disposed about six inches apart more or less in the airway parallel or nearly so with the ventilating current passing through it. An evaporator so constructed exposes a large area of moistened cloth surface and does not obstruct the air current.

In the operation of the apparatus shown in Figs. 1, 2 and 3 the pump 20 takes in water from the collecting reservoir 30 and forces it into the sprayer 10, whence it is discharged in fine streams or spray into the ventilating current F in line with the travel thereof and thence into contact with the evaporator 40, where it trickles down the surface of the latter. The location of the evaporator at a point in the airway a considerable distance from the sprayer and the throwing of the jets or streams into the air current in the direction of the movement of the latter causes the said streams to be elongated and exposed for a considerable distance to the evaporative action of the air and the further exposure of the trickling streams passing down the evaporator, causes the air current to absorb water until it becomes saturated or approximately so. In the so saturated atmosphere the fine particles which would otherwise float in the form of dangerous dust remain stationary and harmless on the ledges and other lodging places in the mine.

The evaporator of Figs. 4 to 7 affords a large trickling surface without obstructing the ventilating current; it however, as in the case of the evaporators in Figs. 1, 2 and 3 may be separated by a suitable interval, from the spraying device. The plates may also be horizontal instead of vertical.

With the exhaust system of ventilation, the evaporators may be suitably disposed along the ribs and roof of the haulage way, which in this case will be the intake. much greater length will thus be required, while complete saturation will also be less certain. In addition such a volume of spray or sprays as are required for complete saturation under adverse conditions, will be objectionable in regard to haulage and travel.

In the use of this invention the air for the intake of the mine becomes saturated with watery moisture to produce, when such air reaches the cooler spaces of the mine, a condition of fog by moisture deposition around the bituminous dust particles, causing them to adhere together and to the Copies of this patent may be walls of the mine spaces. The dust particles are thus made to stick to the floor, to the sides and even to the roof of the mine and they cannot explode as long as they remain lodged.

I claim as my invention:

1. A method of preventing explosions in mines comprising saturating the air for the intake of the mine with watery moisture to produce, when such air reaches the cooler spaces of the mine, a condition of fog by moisture deposition around the bituminous dust particles causing them to adhere together and to the walls of the mine spaces.

2. A method of preventing explosions in mines comprising heating the air for the intake of the mine and saturating said air with watery moisture to produce, when such air reaches the cooler spaces of the mine, a fog by moisture deposition around the bituminous dust particles causing them to adhere together and to the walls of the mine spaces.

3. As a means for preventing explosions in mines the combination with the air intake means of a mine of means for producing a condition of moisture saturation in the air entering the mine, whereby when the said moisture-laden air reaches the cooler spaces of the mine a condition of fog is produced, securing a deposition of moisture around the bituminous dust particles 95 and causing them to adhere together and to the walls of the mine spaces.

4. As a means for preventing explosions in mines the combination with the air intake means of a mine of means for producing a 100 condition of moisture saturation in the air entering the mine and means for heating such air to increase its moisture content, whereby when the said moisture-laden air reaches the cooler spaces of the mine a con- 105 dition of fog is produced, securing a deposition of moisture around the bituminous dust particles and causing them to adhere together and to the walls of the mine spaces.

5. As a means for preventing explosions 110 in mines the combination with the air intake means of a mine of means for producing a condition of moisture saturation in the air entering the mine and means for dis charging steam into said air, whereby when 115 the said moisture-laden air reaches the cooler spaces of the mine a condition of fog is produced, securing a deposition of moisture around the bituminous dust particles and causing them to adhere together and to 120 the walls of the mine spaces.

AUDLEY HART STOW.

Washington, D. G. 

